217

GASTROPODS

(Class Gastropoda - univalves, conches, whelks, etc.)

TECHNICAL TERMS AND GENERAL REMARKS

Gastropod Features

apex

spines

spiral cords

axial ribs

suture

columellar folds

umbilicus

posterior canal

aperture

outer lip

nodules

callus of columella

body whorl

siphonal canal

Glossary of Gastropod Terms

Aperture : the opening in the last whorl, providing an outlet for the head and foot.

Axial sculpture : ribs or growth lines that run parallel to the outer lip.

Operculum : a "trapdoor" grown on the posterior upper part of the foot of a snail. It may be hard and shelly or pliable and made of chitinous, or horny, material.

Periostracum : an outer layer of thin or thick chitinous material covering the outer shell. Sometimes with bristles or hairs.

Radula (plural - radulae) : microscopic hard teeth on a moveable ribbon in the mouth of molluscs, other than bivalves.

Spiral sculpture : cords or threads that encircle the whorls parallel to the sutures.

Spire : the whorls at the top, narrow end, where growth began.

Suture : continuous line on shell surface where the whorls join.

Umbilicus : a central cavity at the base or bottom of the shell.

Whorl : a turn or coil of a snail shell. The body whorl is the last and largest.

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218

GASTROPODS

Even though the gastropod. fauna taken in the various fishing operations is highly diversified, the present guide shows only edible species that are known to be found in markets, or those that may be considered of definity potential interest to fisheries.

Cassis tessellata (Gmelin, 1791)

FAO names : En - Tessellate helmet; Fr - Casque à damier; Sp - Casco teselado.

Size : 26 cm

Habitat : in sandy bottoms from 1 to 50 m depth; rather common

Loc.name(s) :

Crepidula goreensis (Gmelin, 1791)

CASSIDAE

2 or 3 spiral rows of

knobs on shoulder

colour light tan with brown spots

FAO names : En - Goree slipper shell; Fr - Crépidule sandale; Sp - Concha sandalia.

Size : 4 cm.

Habitat : attached to other shells.

Loc.name(s) :

Charonia nodifera (Lamarck, 1816)

FAO names : En - Knobby triton; Fr - Triton noueux; Sp - Tritón buido.

Size : 30 cm

Habitat : coastal waters to 20 m depth.

Loc.name(s) :

Fissurela nubecula (Linnaeus, 1758)

CREPIDULIDAE

exterior smooth

colour white, rayed or speckled in brown

CYMATIIDAE

one rounded varix per

whorl

nodular spiral cords

colour brown, marbled with tan

FISSURELLIDAE

FAO names : En - Cloudy keyhole limpet; Fr - Fissurelle nuageuse; Sp - Fisurela nebulosa.

Size : 2.5 cm.

Habitat : on rocks exposed by the low tide.

Loc.name(s) :

orifice small and oval numerous

fine radial riblets

colour rose or violet with white rays

219

GASTROPODS

interior iridescent, exterior rough HALIOTIDAE

Haliotis tuberculata Linnaeus, 1758 5 or 6 natural holes

FAO names : En - Tuberculate abalone; Fr - Ormeau tuberculeux; Sp - Oreja de mar.

Size : 8 cm.

Habitat : on rocks offshore.

Loc.name(s) : colour brownish grey

MELONGENIDAE

light spiral bands

Pugilina morio (Linnaeus, 1758)

FAO names : En - Giant hairy melongena; Fr - Mélongène noire; Sp - Melongena negra.

Size : 15 cm.

Habitat : in mangrove areas.

Loc.name(s) : colour dark brown, periostracum thick

MURICIDAE

Murex angularis Lamarck, 1822

FAO names : En - Angular murex; Fr - Rocher anguleux; Sp - Cañailla africana.

Size : 5 cm.

Habitat : common among offshore rocks.

Loc.name(s) :

7-11 varices per whorl

bearing about a dozen equal sized, tubular

spines

colour yellow to brownish-black

Murex cornutus Linnaeus, 1758

FAO names : En - Horned murex; Fr - Rocher cornu; Sp - Cañailla cornuda.

Size : 15 cm.

Habitat : among offshore rocks.

Loc.name(s) :

last whorl with two rows of

long, thin spines

siphonal canal long

colour yellowish brown

colour greyish, aperture white

with 3 black spots on columella

220

GASTROPODS

spines longest at top MURICIDAE

Murex duplex Röding, 1789

FAO names : En - Duplex murex; Fr - Rocher duplex; Sp - Cañailla espinuda.

Size : 20 cm.

Habitat : offshore, among rocks.

Loc.name(s) :

Thais coronata (Lamark, 1816)

FAO names : En - Crowned rock shell; Fr - Ovarque couronnée; Sp - Púrpura coronada .

Size : 4 cm.

Habitat : common in mangrove areas.

Loc.name(s) :

Thais haemastoma (Lama rck, 1822)

FAO names : En - Red-mouthed rock shell; Fr - Ovarque bouche de sang; Sp - Boca roja.

Size : 6 cm.

Habitat : subtidal zone, on rocks.

Loc.name(s) :

Thais nodosa (Linnaeus, 1758)

FAO names : En - Nodose rock shell; Fr - Ovarque noueux; Sp - Púrpura nudosa.

Size : 5 cm.

Habitat : below the intertidal zone, on rocks.

Loc.name(s) :

umbilicus deep

6-8 varices per whorl

mouth with rose border

siphonal canal broad

3 spiral rows of large, rounded knobs

axial lamellae

colour dirty grey

sometimes with nodules on shoulder and with

fine spiral threads

colour greyish brown, aperture salmon-pink

5 spiral rows of low, rounded

nodes

221

GASTROPODS

NASSARIIDAE

Bullia miran (Bruguière, 1789)

FAO names : En - Miran bullia; Fr - Bullie de miran; Sp - Bulia de Mirán.

Size : 2.5 cm.

Habitat : intertidal zone, in sandy mud bottoms.

Loc.name(s) :

Natica adansoni Blainville, 1825

FAO names : En - Collar moon snail; Fr - Natice à collet; Sp - Nática engolada.

Size : 3 cm.

Habitat : below the intertidal zone, on sand.

Loc.name(s) :

Natica fulminea (Gmelin, 1791)

FAO names : En - Flamed moon snail; Fr - Natice flammée; Sp - Nática flamante.

Size : 3.5 cm.

Habitat : intertidal zone, on sand.

Loc.name(s) :

darker band below the suture

shell solid, smooth

colour grey

aperture one third of shell

umbilicus with a brown callus almost completely filling it

NATICIDAE

FAO names : En - Adanson's moon snail; Fr - Natice d'Adanson; Sp - Nática de Adanson.

Size : 3 cm.

Habitat : intertidal zone, on sand.

Loc.name(s) :

colour marbled brown, with a yellow band

below

Natica collaris Link, 1807

spiral row of spots

axial brown lines

umbilicus deep, with a small white callus

colour yellowish

zig-zag lines of brownish yellow

umbilicus rounded without a callus inside

colour whitish

shell tan-coloured

222

GASTROPODS

NATICIDAE

Natica marochiensis (Gmelin, 1791)

FAO names : En - Morocco moon snail; Fr - Natice du Maroc; Sp - Nática marroquí.

Size : 2.5 cm.

Habitat : intertial zone, on sand.

Loc.name(s) :

Natica tigrina (Röding, 1798)

FAO names : En - Tiger moon snail; Fr - Natice tigrée; Sp - Nática atigrada.

Size : 3.5 cm.

Habitat : intertidal zone, on sand.

Loc.name(s) :

Natica turtoni E.A. Smith, 1890

FAO names : En - Turton's moon snail; Fr - Natice de Turton; Sp - Nática de Turton.

Size : 3 cm

Habitat : .intertidal zone, on sand.

Loc.name(s) :

Sinum concavum (Lamarck, 1822)

FAO names : En - Concave baby's car; Fr - Natice concave; Sp - Sigarita cóncava.

Size : 4.5 cm.

Habitat : intertidal zone, in sandy bottoms.

Loc.name(s) :

spiral, broken rows of dark brown dots and dashes

umbilicus almost covered by a long, white callus

colour greyish brown

brown spots in spiral rows or tiny dots all over

umbilicus deep with a yellowish callus at centre

aperture violet within

spiral rows of brown dashes

umbiclicus very large, with a large

white callus

aperture violet brown within

colour whitish

animal much larger than shell

223

GASTROPODS

spiral striae

NERITIDAE

Nerita senegalensis (Gmelin, 1791)

FAO names : En - Senegal nerite; Fr - Nérite du Sénégal; Sp - Nerita senegalesa.

Size : 5 cm.

Habitat : intertidal zone, on rocks. Loc.name(s) :

Patella safiana Lamarck, 1819

FAO names : En - Safian limpet; Fr - Patelle safian; Sp - Lepada safiana.

Size : 11 cm.

Habitat : intertidal zone, fixed to rocks.

Loc.name(s) :

Strombus latus Gmelin, 1791

FAO names : En - West African stromb; Fr - Strombe d'Afrique occidentale; Sp - Cobo de Africa occidental.

Size : 14 cm.

Habitat : coastal waters to 10 m depth.

Loc.name(s) :

Cymbium cymbium (Linnaeus, 1758)

FAO names : En - Pig's snout volute; Fr - Volute trompe de cochon; Sp - Voluta trompa de cerdo.

Size : 15 cm.

Habitat : offshore waters, on sand.

Loc.name(s) :

parietal wall pustulose, white, with 2 or 3 teeth colour blackish

PATELLIDAE

shell oval slightly

elevated narrower in front,

but shape and

sculpture variable

about 100 fine

radial riblets

colour grey, interior bluish grey

STROMBIDAE

3 spiral rows of tubercles; the top one having knobs

apex mammilliate

shell maculated in brown, rose and white

top of shell flattish VOLUTIDAE

outer surface glossy smooth

shell subcylindrical

colour pale yellowish brown

colour orange, perīostracum brown

224

GASTROPODS

dished-out apex VOLUTIIDAE

Cymbium glans (Gmelin, 1791)

FAO names : En - Elephant's snout volute; Fr -Volute trompe d'éléphant; Sp - Voluta trompa de elefante.

Size : 35 cm.

Habitat : offshore waters, on sand.

Loc.name(s) :

Cymbium pepo (Lightfood, 1786)

FAO names : En - Neptune's volute; Fr - Volute Neptune; Sp - Voluta de Neptuno.

Size : 27 cm.

Habitat : offshore waters, on sand.

Loc.name(s) :

shell thin, but strong, cylindrical

colour greyish brown, glossy

apex hardly visible

shell globular

aperture very large

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